This invention relates generally to the detection of defects in cured and uncured tires. More specifically this invention relates to the detection of defects in the sidewalls, such as for example: missing wires, uneven spacing between adjacent wires, and variances in the gauge of the tire sidewall.
Various methods and systems have been used to inspect various parts of tires, such as for example ultrasonics, microwaves, X-rays, etc. Most systems however have not lent themselves to be used in production settings because of one or more various problems. These have included too slow of a cycle time, the cost of the equipment, and the accuracy of the results. As a result 100% testing of tires has not been practiced and has resulted in a sampling approach relating to the tires produced.
It still is however, desirous in the industry to provide a means for testing tires in a production line where virtually all tires are tested. The sidewall area of a tire is one such area where it is desirous to inspect all the tires in a production line.
In one embodiment, the present invention relates to a system for inspecting tire sidewalls by detecting missing or overlapping cords within an elastomer of the sidewalls of a tire, the system comprising: (a) a radiation source or sources for providing a collimated beam of radiation through each tire sidewall, the radiation being less attenuated or reflected by the elastomer of said sidewalls than by the cords: (b) a sensor or sensors aligned in combination with each radiation source, each sensor or sensors detecting the collimated radiation and generating an electrical signal in response to the radiation: (c) a positioning arm, the radiation source or sources and the sensor or sensors being attached to the positioning arm: (d) a positioning means for causing said positioning arm to interpose a tire sidewall between each radiation source and sensor; (e) a means for causing each radiation source and sensor to scan along a section of the tire sidewall at a predetermined speed; (f) means responsive to the electrical signal generated by each sensor for providing a timing signal when each said sensor bears a predetermined relationship to each scanned cord in the tire sidewall; and (g) means responsive to said timing signal associated with each sensor during a predetermined scan for mesasuring the time each scanned cord is between a radiation source and a sensor.
Also provided is a method of detecting defects in tire sidewalls, the method comprising the steps of: (a) interposing a tire sidewall between a radiation source or sources and a sensor or sensors: (b) passing a collimated beam of radiation from a radiation source or sources through a tire sidewall, such radiation being less attenuated or reflected by the elastomer of the sidewall than the scanned cords: (c) detecting radiation passing through a tire sidewall by a sensor or sensors; (d) causing each radiation source and sensor to scan along a section of tire sidewall at a predetermined speed: (e) providing a timing signal, responsive to an electrical signal received by a sensor when a sensor bears a predetermined relationship to each scanned cord in the tire sidewall: (f) measuring the time each scanned cord is between a radiation source and a sensor, responsive to the respective timing signal generated.